I purchased an extra Eaton M90 Gen III off craigslist that i wanted to do a port and polish on. I Have never ported or polished anything and wanted to take my time doing it. Before i started to hog out the blower i did a lot of research about porting and polishing. I came to the big debate about filling the silencer holes in the output plate to increase the noise of the supercharger. Some people say its a huge risk of using jb weld or aluminum epoxy to fill the slots. If the bond fails it will fall out into the lim and grenade the motor. I do agree that it is not worth the risk of doing it the way people are talking about. So i think i came up with a safe way to block the silencer slots and not worry about bond failure and blowing your motor. I did this to my supercharger and it seems to be working great. This really lets the supercharger scream at high RPM's.
The first step is to port and polish your supercharger, Im not going into the ways of how to do the porting on it, this is simply how to block the silencer slots safely
As you see above this is a ported supercharger with the H bar removed, i did this because in the future i am planning
on doing an IC Setup. If you have no plans to IC then leave it there.
The next thing i did was take some thick photo paper and made a template on the output plate
Be sure to make the paper template the exact size so it fits in there as tight as possible including the tabs on the outside that fill in the
tips of the silencer ports like shown here.
Next you will need a sheet of aluminum about 1/4 to 3/8 thick. you can purchase from your local hardware store like LOWES.
Place you paper template on the aluminum and trace it out with a marker.
After you trace it out start cutting it out with a dremel or what ever tools you have access to. Be sure to cut on the outside of the template where the x's are and leave the black outline. You want to make the piece too big to fit into the supercharger so you can slowly trim it down and get the tightest fit possible.
Then start cutting it out, and (TAKE YOUR TIME)
Once you have it cut out take some sand paper and lightly sand down the sharp edges so you don't cut yourself.
now that you have it cut out and sanded the edges try to place it inside the supercharger it should be a little larger than it needs to be this is where you take a grinder and slowly take the marker off the edges making it smaller so it will eventually sit real snug down into the output plate. you want it to where you have to push it hard to get it inside flush and flat.
as you see here the plate fits snug and stays in place with out holding it there. I only grinded down the outside edge of the plate and not the inside edge. I will get to this later there is still a ledge on the inside of the triangle where the plate has a smaller opening then the triangle on the supercharger. (LEAVE IT THERE)
Next you want to scrape the surface up on the supercharger output area and the side of the plate that touches the supercharger output.
Make it like th pictures above, i used a dremel with a cutting wheel and let it bounce and scar the surface up so it was rough. I then used Carb Cleaner and sprayed the surface then scrubbed it with a wire brush and sprayed it again. Now that everything is clean and ready for a good bond tape off teh inside of the supercharger like below.
Next you want to mix up your JB WELD, make alot of it, Ratio is 1 to 1. Pour it onto the supercharger case and leave it about 3/8 thick all the way around and press your plate inplace. I used some grips to help push the plate down. allow the jb weld to flow out of all the edges like below.
Now Let it Set like this for 24 Hours and leave it alone. After you waited 24 hours pull the tape off.
It should now look like this. I let mine bake in the sun for a good 6 hours so it got real hot. Try to pick at the jb weld and make sure it is rock hard. If so then the next step is to grind everything down back to bare aluminum and try to leave as little jb weld as possible like so.